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BMW Differential and Gearing Upgrades

Upgrading various parts of the differential can have tremendous benefits in your car's performance. It's easy to forget that the differential is a source for making your car faster and handle better so it's often overlooked. The engine is not the only place to make the car faster. Our differential options vary from gearing upgrades to limited slip conversions. You can purchase the ring & pinion gear sets on their own (professional installation required) or have us build a diff around your own specifcations. The options are almost endless! Every custom-built diff is fully rebuilt with seals and bearings. We also design and supply bushing options to reduce driveline wind-up, finned differential covers for better cooling, and more!

Ratio Changes - Changing the differential gearing is one of the best and most-effective upgrades you can make on any BMW (old or new). By using a shorter (numerically higher) final drive ratio you are increasing your RPM relative to road speed - this puts you in a more powerful RPM range than before! Since you're in a 'meatier' part of the power band you're now putting down more power/torque to the ground. If you can trade outright top speed for faster acceleration at daily speeds then this is the perfect upgrade for you.

Limited Slip Upgrades - Sadly, many BMWs today are not equipped with a limited slip (posi-traction) differential. BMW has tried to compensate by using traction control that cuts power at the engine or applies the brakes to retard wheel spin (or a combination of both). But nothing beats the function and feel of a a true LSD which may be why BMW continues to use them in M cars. Our LSD upgrades can be done a number of different ways - a factory-type limited slip unit with either 2 or 3 clutch packs, helical type, OS Giken unit, or something truly custom. We can also vary ramp angles and setup to change the limited-slip behavior under acceleration, deceleration, and cornering. Need a custom diff? Call or e-mail to have a quote.

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Packaged by Turner - Corporate Logo
T#:56327180
Part#: F3XAWDFDKT5
In Stock
New Item
Sale - Save 1% $ 104.99

This product was last offered at the strikethrough price on
08-04-2026

$ 103.54 USD
Free Shipping on orders $49 and up
Sale - Save 1%
$ 104.99

This product was last offered at the strikethrough price on
08-04-2026

$ 103.54 USD
Free Shipping on orders $49 and up
This kit combines Red Line 75W85 GL-5 Synthetic Gear Oil with Rein OEM replacement plugs in order to perform a full drain and fill service on both of your differentials
Packaged by Turner - Corporate Logo
T#:56038061
Part#: E9XSBFRDFFBKT2
In Stock
New Item
$ 491.99 USD
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This complete upgrade package is designed to put an end to steering slop. Utilizing a high performance 95A durometer polyurethane formulation, this kit replaces the mushy OEM rubber with proven rigidity.
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Packaged by Turner - Corporate Logo
T#:56327200
Part#: F3XAWDFDKT6
Ships in 2 Business Days
New Item
$ 154.99

This product was last offered at the strikethrough price on
08-07-2026

$ 154.52 USD
Free Shipping on orders $49 and up
$ 154.52 USD
Free Shipping on orders $49 and up
This kit combines Motul 75W85 GL-5 Synthetic Gear Oil with Rein OEM replacement plugs in order to perform a full drain and fill service on both of your differentials

Packaged by Turner - Corporate Logo
T#:56471655
Part#: 27102413711KT3
Ships in 3 Business Days
New Item
$ 228.99 USD
Free Shipping on orders $49 and up
This Transfer Case Repair Kit provides an exact-fit, OEM grade solution engineered to rebuild the servomotor assembly back to factory operating specifications. Designed for enthusiasts who demand crisp power transfer and exact mechanical feedback from their drivetrain.
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Packaged by Turner - Corporate Logo
T#:56471654
Part#: 27102413711KT2
Ships in 3 Business Days
New Item
$ 228.99 USD
Free Shipping on orders $49 and up
This Transfer Case Repair Kit provides an exact-fit, OEM grade solution engineered to rebuild the servomotor assembly back to factory operating specifications. Designed for enthusiasts who demand crisp power transfer and exact mechanical feedback from their drivetrain.
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Packaged by Turner - Corporate Logo
T#:56616382
Part#: 27111226467KT3
Ships in 7 Business Days
New Item
$ 48.99 USD
Free Shipping on orders $49 and up
This Transfer Case Service Kit replaces degraded fluid and sealing hardware to maintain proper lubrication within the all wheel drive transfer case. Unserviced transfer case fluid breaks down into sludge and deposits, causing lubrication loss and internal component wear; this service kit prevents internal wear by renewing fluid properties and drain hardware.
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Packaged by Turner - Corporate Logo
T#:56616376
Part#: 27111226467KT2
Ships in 7 Business Days
New Item
$ 48.99 USD
Free Shipping on orders $49 and up
This Transfer Case Service Kit replaces degraded fluid and sealing hardware to maintain proper lubrication within the all wheel drive transfer case. Unserviced transfer case fluid breaks down into sludge and deposits, causing lubrication loss and internal component wear; this service kit prevents internal wear by renewing fluid properties and drain hardware.
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Packaged by Turner - Corporate Logo
T#:56471658
Part#: 27102413711KT5
Ships in 3 Business Days
New Item
$ 228.99 USD
Free Shipping on orders $49 and up
This Transfer Case Repair Kit provides an exact-fit, OEM grade solution engineered to rebuild the servomotor assembly back to factory operating specifications. Designed for enthusiasts who demand crisp power transfer and exact mechanical feedback from their drivetrain.
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Packaged by Turner - Corporate Logo
T#:56471657
Part#: 27102413711KT4
Ships in 3 Business Days
New Item
$ 228.99 USD
Free Shipping on orders $49 and up
This Transfer Case Repair Kit provides an exact-fit, OEM grade solution engineered to rebuild the servomotor assembly back to factory operating specifications. Designed for enthusiasts who demand crisp power transfer and exact mechanical feedback from their drivetrain.
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Packaged by Turner - Corporate Logo
T#:55965861
Part#: 30309175WKWVTKT2
Ships on Aug 27, 2026
New Item
$ 1,269.99 USD
Free Shipping on orders $49 and up
This AutoTech LSD Upgrade Kit pairs AutoTech’s highly engineered 188mm limited-slip differential carrier with a pair of Corteco output shaft seals, giving you everything you need for a leak-free install.
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